Airplane wing leading edge construction



May 17, 1949. RE. BARRICK ETAL 8 7 AIRPLANE'WING LEADING- EDGE CONSTRUCTION Filed 001:. 7, 1947 4 Sheets-Sheet 1 May 17, 1949.. R. E. BARRICK ET AL 1 2,470,128 A AIRPLANE WING LEADING EDGE CONS-TRUCTION I I 4 Sheets-Sheet 2 File d Oct. 7. 1947 May 17, 1949. R. E. BARRICK EIAL AIRPLANE WING LEADING EDGE CONSTRUCTION 4 Sheets-Sheet 5 Filed Oct. 7, 1947 m N M M u I I I mg n I h v 7a R m a, n V/ M I, l .w W v m I\ n h m a L May 17, 1 949.. R. E. BARRICK ETAL 2470,128

AIRPLANE WING LEADING EDGE CONSTRUCTION Filed Oct. 7, 1947 4 Shets- Sheet 4 iflll navy xcfr,

Patented May 17, 1949 AIRPLANE WING LEADING EDGE CONSTRUCTION Ray E. Barrick, Baltimore, and Ayers Morison, Brooklandville, Md., assignors to The Glen L. Martin Company, Middle River, Md., a corporation of Maryland Application October 7, 1947, Serial No. 778,406

3 Claims.

This invention relates to airplane wing construction, particularly that of the leading edge .whereby the structure of the wing affords the advantages of excellent strength characteristics, coupled with ease of fabrication and anti-icing ducts provided by the inherent strengthening members in the leading edge structure. The disadvantages and inherent weaknesses of current anti-icing or de-icing systems for aircraft are now well known. Most of the systems in use require rubber boots attached to the external surface of the wing, which are put on in winter months and removed in summer months. Such systems cause great difliculty from the maintenance, storage and deterioration considerations,

but are most objectionable in that in modern, high speed airplane wings where the contour is critical, the attaching of the boot has an undesirable eifect on the aerodynamics of the wing. All such anti-icing systems add their weight 100% to the gross weight of the airplane, in that their physical structure cannot be used for anything else and, in fact, detracts from the aerodynamic characteristics of the airplane, which further reduces the pay load of the airplane.

It is an object of this invention to provide an airplane wing panel construction employing a box beam spar having great inherent strength.

It is another object of this invention to provide a reinforced, removable nos-e section for attachment to and cooperation with the wing panel to provide a smooth external surface and increased spar strength.

It is another object of this invention to form a wing panel having a forward spar of a box beam or channel construction which affords an exhaust duct for the hot gas employed for deicing which is a primary load bearing member in the airplane wing construction.

It is another object of this invention to overcome current defects in de-icing systems noted above by providing an anti-icing system, the components of which are integral structural members of the leading edge of the airplane wing.

It is a further object of this invention to provide an anti-icing airplane wing leading edge construction that has no structure that must be added externally of the wing to alter the aerodynamic characteristics of the wing.

It is a further object of this invention to provide an airplane wing leading edge construction that has removable sections cooperating to form a hot gas duct along the leading edge of the wing for anti-icing purposes.

- It is a further object of this invention to provide exhaust vents at the trailing edge of the wing tip to exhaust the gas used for de-icing purposes from the wing.

Further and other objects of this invention will become apparent from the description of the accompanying drawings which form a part of this disclosure and in which like numerals refer to like parts. I

In the drawings:

Figure 1 is a plan view of an airplane wing embodying the invention.

Figure 2 is an exploded View of the airplane wing leading edge construction.

Figure 3 is a section taken on the line 33 of Figure 6.

Figure 4 is an enlarged fragmentary sectional View of the joint between the wing panel and the nose section of the wing.

Figure 5 is a fragmentary sectional view taken onthe line 55 of Figure 4.

Figure 6 is a sectional view taken on the line 6-45 of Figure 3.

Figure 7 is a perspective view of the underside of the trailing edge of the airplane wing showing the vents in the wing tip section.

The airplane wing construction shown in the drawings illustrate the preferred embodiment of the invention.

Figure 1 of the drawings shows the wing l of an airplane secured to fuselage 2. The wing shown consists of an inboard panel 3 supporting the engine nacelle 4, an outboard wing panel 5, and a wing tip section 6. Flap structure I and aileron 8 extend along the trailing edge of the wing. I The nose portion of the wing is formed by nose sections 9 which are removably secured to wing panels 3 and 5. Nose sections 9 extend along the leadingedge of the wing and form ducts for hot air for anti-icing purposes.

The leading edges of wing panels 3 and 5 are formed by box beams consisting of a corrugated channel member [0 having its sides secured to the flanges of T section H. Member I2 is a corrugated sheet extending between the webs of the flanges of the T section for strength. Member 12 may be continuous in the area of the wing panel used for fuel storage, or in the outboard section it may be skeletonized where the web is unnecessary for a backing member or for strength. Rib portion l3 extends forward of the corrugated wall 14 of channel l0, spaced at the intersection of the adjoining edges of members 9. Rib portion I5 extends transverse of channel H! aligned with member 13. Members [3 and i5 have holes It and I! that serve as lightening holes and aiiord communication between the ducts formed by the box beam spar and the nose member 9 of the wing.

It will be seen then that the wing panel has a box beam spar formed by members Ill, H and i2 extending along the leading edge of the wing panel which aifords not only great strength as an airplane structural member but also provides a duct for hot gas as a part of the anti-icing system.

The particular construction of the box beam spar for the wing panel and the nose'portion is best shown in detail in Figures 2 to 6. The. Ex, ploded view, Figure 2, shows channel member ID formed with corrugations i8 inwardly of the sheet on the sides of the channel. Similar corrugations are provided in wall M of channel Ill. The channel, having transverse corrugations, provides a relatively strong member which, when attached to extrusion H with corrugated web [2 extending therebetween, provides a wing panel box beam spar construction of great strength. Outer skin I9 is secured to one of the flanges of the T section ll. Skin portion 2|] is secured to another flange of T section II with the sides of channel it! abutting skin ii! to form a continuous smooth profile over a portion of the sidesof channel i0. corrugations l8 in the sides of channel l0 afford passages when skin 2 is in place along the sides of the channel member It; Apertures 2| formed in the ends of corrugations l8 afiord communication between these passages and the interior of the box beam spar. The leading edge of the wing panel, therefore, is formed by a box beam consisting of members It, H and i2. The skin section 2!! affords a smooth contour over the exterior of the box beam except for the portion to which the nose section is attached and also affords passages through corrugations l8 and apertures 2| along skin communicating with the interior of the box beam spar.

Nose portion 9 is assembled with the leading edge of the wing panel, to complete the airfoil profile. Skin member 22 consists of an outer, smooth sheet reinforced with a corrugated sheet 23 secured thereto to stiffen the outer skin mem her and to provide passages from the open ends 2-4 of corrugations 25 to apertures 26' located along the inside of the leading edge. adjacent the attaching flange to accommodate strip 27 which gives additional strength around the attaching screw openings. A similar reinforcing member 28 is employed between the outer skin 2% and the corrugated sides of channel I0 adjacent the attaching edge of the structure. This is best shown in Figure 4. This figure also shows that when the edges of nose portion 9 are put in place upon the forward portion of the wing panel, the open ends of corrugations 25 in sheet 23- nest in the corrugations l8 of the side portions of channel It. It will be thus seen that when member 9 is in place on the leading edge of the wing panel, a continuous passage for hot gas is afforded from the interior of member 9 through apertures 25, corrugations 25, the open ends of the corrugations 24, corrugations l8 and apertures 2 i to the interior of the box beam spar forming the leading edge of the wing panel.

The nesting of corrugations 25 in i8 is shown in sectional view Figure 5.

So that the temperature of the gas will be maintained at a high level uniformly along the leading edge duct, a pad of insulation material 29, preferably glass wool retained by glass cloth,

Sheet 23 is formed 4 is secured in brackets 30 to the outside of wall ll of member l0. Similar insulating pads 3| and 32 are provided along the inside corrugation sheet of member 9, to insulate the duct formed by member 9 and maintain the temperature of the gas flowing therethroughr The hot. gas. that escapes from this duct through aperture 26 heats the skin by conduction and radiation from the passages formed by corrugations 25 and I8. The hot gas can be supplied from any conventional source, such as engine exhaust gas heat exchangers or'combustion heaters.

The outboard end of the outer wing panel is completed by wing? tip section B which is hollow 1 and affords-passage for the exhaust gas from the anti-icing system from the hollow spar or interior of the wing. panel through vents 33 formed by spacers 34 between the upper and lower skins at the trailing edge of wing tip section 6.

The above described structure provides a novel airplane wing construction which the strength of the structure is obtained by structural elements so arranged that these same elements can be used as elements of a de icer system. The wing panel has aforward' boxbeam spar of novel construction from which is obtained great strength. When the nose section is secured in place; the forward. portion: of the wing has in eiiect a double-box beam. By insulating the nose portion and using. it as a diict for hot-gas, de-icing or anti=icing is effected with no additional structural elements.

It is to be understood that certain changes, alterations, modifications and substitutions can be made without departing'from thespirit and scope of the appended claims. I

We claim as our invention:

1. An airplane wing construction including upper and lower sheet metal skins, a channel member extending spanwise of the wing secured to said upper andIower skins with the forward edges of said skins partially overlapping the sides of said channel member, said channel member havin}; transverse corrugations fanned therein, the

- ihg open COIhmIiHiCatiOIi with the interior of the wing, a nose portion removably secured to said channel ii e'mber including a U-shaped smooth outer skin having the edges thereof abutting the edges of said upper and lower wing skins, a corriigate'd under skin for said nose portion secured thereto, the open ends of the corrugations of said urider'skih nesting in the corrugations of the sides of said channel member, orifice means formed in the corrugations of said under skin which afford communication between the interior of the said U=shaped nose portion, through the passages formed by said corrugations, and the interior of said wing.

2; An airplane wing leading edge construction including a spar extending spanwise of the wing, a channel member having transverse corrugations, secured to the spar formin therewith a box beam, outer skin secured to the sides of said channel conforming to the anion profile of the T- tiori adjacent said spar, orifice means formed in the ends of the corrugations adjacent said spar afiording communication between the space intermediate the sides of said channel member and said skin attached thereto and the interior or said box beam, a U-shaped nose p'ortion comprising a smooth outer skin, the edges of which abut said skin on said cha-hnel members to complete the airfoil contour, acorrugated reinforcing sheet secured on the inside of said smooth skin on said nose portion, the corrugations of said reinforcing sheet nesting in the corrugations of the sides of said channel member, orifice means formed in the corrugations of said reinforcing sheet affordin communication between the space intermediate said smooth outer skin and said corrugated reinforcing sheet and the interior of said nose portion.

3. An airplane wing construction including upper and lower skins, a channel member having transverse corrugations extending spanwise of the wing secured to said upper and lower skins with the forward edge of said skins partially overlapping the sides of said channel member, the rear end of the corrugations on the sides of said channel formed to be in communication with the interior of the wing, a nose portion removably secured to said channel member including a U-shaped smooth outer skin havin the edges thereof abutting the edges of said upper and lower wing skins, a corrugated under skin for said nose portion secured thereto, the open ends of the corrugations of said under skin nesting in the corrugations of the sides of said channel member, orifice means formed in said corrugations of said under skin which afford communication between the interior of said U-shaped nose portion, through the passages formed by said corrugations, and the interior of said wing.

RAY E. BARRICK.

AYERS MORISON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

